Materials of medical instruments and prostheses inserted into the human body are in direct contact with blood, tissue, organs and the like, and need to be accompanied with stability, and such materials are referred to as biocompatible materials. Various preparation methods have been studied in order to develop biocompatible materials. Particularly, development of new materials by crosslinking biocompatible materials that have been developed in the art to supplement individual properties of these materials has been accelerated.
Hyaluronic acid and derivatives thereof have high viscosity, excellent biocompatibility and complete biodegradability, and have been used in a wide range of applications.
However, hyaluronic acid and derivatives thereof are readily degraded by heat and bio-enzymes (hyaluronidase and the like) losing an inherent nature of hyaluronic acid. In prostheses inserted into the living body, fast biodegradability and loss of an inherent nature make a cycle of prosthesis insertion into the human body short, and become a factor impairing performance as prostheses by decreasing viscosity and elasticity. For example, general hyaluronic acid fillers have retention length of 6 months to 1 year in the living body, however, original viscosity and elasticity are readily lost within the period causing a problem.
As a result, hyaluronic acid and derivatives thereof secure biocompatibility, but need to supplement disadvantages of shortening a remodeling procedure cycle of fillers and the like. In addition, when prostheses and the like are degraded inside the living body, the degraded products should not adversely affect the human body and need to bring advantageous effects.